1. Field of the Invention
The present invention relates to an inkjet recording apparatus, and in particular, relates to an inkjet recording apparatus that discharges ink through a recording head removably mounted on a carriage to perform recording.
2. Description of the Related Art
A tube supply method is one of known ink supply methods allowing an inkjet recording apparatus to perform a high volume of printing or printing on a large sheet with a low ink-replacement frequency.
A carriage structure for the tube supply method requires a member through which a recording head is mounted on and fixed to a carriage and a joint mechanism, serving as a passage connecting member, for connecting an ink supply tube to the fixed recording head. As for the joint mechanism for connecting the recording head and the ink supply tube, a method of inserting a needle pipe connected to the ink supply tube into a sealing member provided for the recording head is often used. The sealing member is formed of rubber, for example. Accordingly, the sealing performance of the passage can be ensured.
Using multiple color inks requires a plurality of joint mechanisms for supplying the inks from different ink tanks to liquid discharge portions in the recording head. An extremely large force is therefore needed to simultaneously insert a plurality of needle pipes into the sealing members to connect the joint mechanisms to the recording head. Accordingly, an operating member for the joint mechanisms is used to easily connect the joint mechanisms to the recording head.
For this reason, the carriage structure for the tube supply method requires an operating member (recording head operating member) for fixing the recording head to the carriage and an operating member (joint mechanism operating member) for connecting the joint mechanisms to the recording head. Since these operating members are typically intended to be separately operated, a wrong operating member may be operated. If such a wrong operation is performed, the accurate connection between an ink supply system and the recording head is lost. Disadvantageously, this results in ink leakage and failure of ink discharge may occur. In addition, the joint mechanisms or components of a print cartridge may be damaged or broken.
To solve the above-described disadvantages, a configuration including the recording head operating member, the joint mechanism operating member, and a wrong operation preventing unit for these operating members. Japanese Patent Laid-Open No. 2002-234179 discloses a configuration in which the recording head cannot be replaced unless the recording head operating member and the joint mechanism operating member are operated in the correct order. For example, to remove the recording head, the joint mechanism operating member is first operated to separate the recording head from the ink supply system and the recording head operating member is operated, and the recording head is removed. If the operating members are operated in an incorrect order, the operating members interfere with each other, so that a user can recognize that the user has operated an incorrect operating member.
Inkjet recording apparatuses need replacement of a recording head in order to maintain printing quality. Some inkjet recording apparatuses are designed so as to allow a user to replace a recording head. When the user replaces the recording head, the recording head may be replaced in an incorrect procedure, alternatively, the user may perform a wrong operation at unintended timing. For example, if a recording material (print sheet) becomes jammed in the inkjet recording apparatus, the user may accidentally operate the joint mechanism operating member upon opening a cover of the apparatus. If the user performs such a wrong operation, ink stored in the ink supply system, such as an ink supply tube, may scatter and adhere to the user or a printed material. In some cases, a remarkable amount of ink leaks from the ink supply system. Unfortunately, the inkjet recording apparatus or components of the recording head may be damaged or broken.
According to a technique disclosed in Japanese Patent Laid-Open No. 2002-234179, the joint mechanism operating member can be operated separately from the other operating member. Disadvantageously, this technique cannot address such a problem that the joint mechanism operating member is accidentally operated during operation of the inkjet recording apparatus and ink leakage is caused.